<?php
$num_post		= 3; 
$post_type		= 'tour'; 
$taxonomy		= 'category'; 
$field			= 'slug'; 
$metakey1		= $wpdb->prefix.'display'; 
$metavalue1		= 'display';
$metakey2		= $wpdb->prefix.'hotel_best'; 
$metavalue2		= 'display';
$term			= 'in-vietnam';
 
$args = db_query_posts_in_terms_child_multi_nopage($num_post, $post_type, $taxonomy, $field, $term, $metakey1, $metavalue1,$metakey2, $metavalue2);